Method for boiling-off of blended fabric from polyamide fiber and polyurethane fiber, method for producing dyed blended fabric and dyed blended fabric

ABSTRACT

A method for scouring a mixed fabric of polyamide fibers and polyurethane fibers is provided, wherein soft water as treating water is used and the treating water contains a sequestering agent. According to the present invention, a mixed fabric of polyamide fibers and polyurethane fibers in which uneven dyeing hardly arises, that is, excellent leveling is achieved, is provided.

[0001] TECHNICAL FIELD

[0002] The present invention relates to a method for scouring mixed fabrics of polyamide fibers and polyurethane fibers, a method for manufacturing dyed mixed fabrics, and dyed mixed fabrics.

[0003] The present invention more particularly relates to a method for scouring a mixed fabric of polyamide fibers and polyurethane fibers, a method for manufacturing a dyed mixed fabric, and a dyed mixed fabric, in which the mixed fabric is effectively scoured by removing stains or oil smears and is excellent in leveling.

[0004] BACKGROUND ART

[0005] Polyurethane fibers are used for many kinds of wear such as innerwear, pantyhose, swimming wear, leotards, and outerwear because of their excellent characteristics such as stretching properties, shape retention, fitting properties, formability, unique texture, and crease resistance.

[0006] Since pliable and soft texture is necessary for wear such as innerwear, pantyhose, swimming wear, leotards, and outerwear, which are in contact with the skin directly, knitting is usually used for the fabrics of such wear. Polyamide fibers such as nylon fibers are mainly used for mix materials.

[0007] When used for outerwear, polyurethane fibers are mixed with polyamide fibers, polyester fibers, and natural fibers such as wool and cotton, and the resulting fibers are usually knitted.

[0008] Polyurethane fibers are mixed and are used for nonwoven fabrics, which are elastic. Since stretching properties and fitting properties are necessary for wear such as innerwear, pantyhose, swimming wear, and leotards, the content of polyurethane fibers has been increased. There is a problem in that oil is apt to adhere to materials including polyurethane fibers. Smears on knitting due to oil used in knitting machines have been increasing due to the diversity of mix materials, the complexity of knitting structure, and high-speed knitting operation. Furthermore, the removal of oil in a scouring step is difficult due to contamination of metals in the oil, such as iron or copper used for lube oil pipes for knitting machines or knitting machine needles.

[0009] An acid dye usually used for dyeing polyamide fibers has a poorer migration than that of a disperse dye usually used for polyester fibers. Thus, in the dyeing process of mixed fabrics of polyamide fibers and polyurethane fibers, when contaminants such as oil smears are not thoroughly removed in a scouring step before a dyeing step, product deficiency such as dyeing specks or oil smears arises.

[0010] Hitherto, mixed fabrics of polyamide fibers and polyurethane fibers are usually scoured with nonionic surfactants, anionic surfactants, or amphoteric surfactants. Furthermore, alkalis such as soda ash or caustic soda are generally added into a solution containing a surfactant in order to improve the scouring effects. However, since oil smears are not sufficiently removed in a scouring step by such a method, problems due to dyeing specks or oil smears have arisen.

[0011] As a scouring method for a mixed fabric of polyurethane fibers having much oil adhering to it, the following method is disclosed in Japanese Unexamined Patent Application Publication No. 12-80562: pretreatment is performed using a treating solution containing a high nonionic surfactant content at a low bath ratio, and then scouring is performed using another treating solution containing a low nonionic surfactant content at a high bath ratio. The above method is excellent in removing oil but is not substantially effective in the removal of smears containing metals and in the prevention of oil smears.

[0012] In order to decrease problems such as dyeing specks or oil smears in a dyeing step, the following methods have been proposed: a method in which a dyeing solution containing a sequestering agent is used, and another method in which an acid dye excellent in leveling is used. However, such methods have small effects and cause a decrease of color fastness in some cases.

DISCLOSURE OF THE INVENTION

[0013] It is an object of the present invention to provide a method for scouring a mixed fabric of polyamide fibers and polyurethane fibers, a method for manufacturing a dyed mixed fabric, and a dyed mixed fabric, in which the formation of dyeing specks or oil smears due to oil contaminants is inhibited.

[0014] As a result of intensive research, the inventors have solved the above problems.

[0015] The present invention provides a method for scouring a mixed fabric of polyamide fibers and polyurethane fibers, wherein soft water as treating water is used and the treating water contains a sequestering agent.

[0016] The present invention further provides a method for continuously scouring a mixed fabric of polyamide fibers and polyurethane fibers, wherein treating water after finishing scouring treatment contains an unreacted sequestering agent.

[0017] The present invention further provides a method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers, wherein the method comprises the steps of scouring a mixed fabric of polyamide fibers and polyurethane fibers, presetting the mixed fabric at 190° C. or less for at least 60 seconds, dyeing the mixed fabric, and finishing the mixed fabric.

[0018] The present invention further provides a method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers, wherein the method comprises the step of dyeing a mixed fabric of polyamide fibers and polyurethane fibers with an acid dye, wherein soft water as a dyeing solution is used and the dyeing solution contains a sequestering agent.

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] The present invention will now be described in detail.

[0020] Polyamide fiber used in the present invention is not specifically limited as long as the fiber is composed of polyamide. The fiber is preferably composed of polyamide 6 (nylon 6) or polyamide 66 (nylon 66). Alternatively, a copolymer of a polyamide 6 component and a polyamide 66 component, and another copolymer of other polyamide components may be used for the fiber.

[0021] Polyurethane fiber used in the present invention is preferably manufactured as follows: a polymer diol, an isocyanate containing an organic diisocyanate as the main component, and a polyfunctional active hydrogen component are allowed to react, and then the resulting polyurethane polymer is spun.

[0022] Exemplary polymer diols include polyether glycols, polyester glycols, polycaprolactone glycol, and polyhexamethylene dicarbonate glycol, wherein the polyether glycols include polytetramethylene glycol, polyethylene, and propylene ether glycol, and the polyester glycols are obtained by allowing at least one glycol such as ethylene glycol, 1,6-hexanediol, 1,4-butanediol, and neopentyl glycol to react with at least one dicarboxylic acid such as adipic acid, suberic acid, azelaic acid, sebacic acid, β-methyladipic acid, and isophthalic acid. The above polymer diols may be used alone or in combination.

[0023] Exemplary organic diisocyanates used for the polyurethane fiber used in the present invention include 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and isophorone diisocyanate. The above organic diisocyanates may be used alone or in combination. Furthermore, a small amount of triisocyanate may be used in combination.

[0024] Exemplary polyfunctional active hydrogen components include ethylenediamine, 1,2-propylenediamine, hexamethylenediamine, xylylenediamine, 4,4′-diphenylmethanediamine, hydrazine, 1,4-diaminopiperazine, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and water. The above component may be used alone or in combination. The above component may also be used with a small quantity of terminators such as monoamines and monoalcohols.

[0025] The polyurethane fiber used in present invention may contain an oxidation inhibitor such as 2,6-ditetrabutylparacresol and phosphorous ester, a light or ultraviolet absorber such as hydroxybenzophenone or hydroxybenzothiazole, an anti-yellowing agent such as 1,1-dialkyl substituted semicarbazide and dithiocarbamate, and a white pigment such as titan oxide or zinc oxide.

[0026] According to the present invention, the above polyurethane is used in solution. A solvent for the polyurethane is not specifically limited as long as the solvent does not react with polyurethane, and preferably has a superior ability to dissolve polyurethane. The solvent preferably includes, for example, N,N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide, and vinylpyrrolidone. The polyurethane content is not specifically limited, and is preferably 25% by weight to 80% by weight, and more preferably 35% by weight to 55% by weight. When the content is less than 25% by weight, spinning is apt to be difficult due to the increasing heat required to vaporize the solvent. On the other hand, when the content exceeds 80% by weight, spinning is also apt to be difficult due to a decline in the stability of the solvent. When the degree of polymerization of polyurethane is decreased in order to improve the stability of the solution, the quality of polyurethane fibers is apt to decrease.

[0027] According to the present invention, polyurethane fibers may be manufactured by dry, wet, or melt spinning using a solution containing polyurethane.

[0028] The fineness of the polyurethane fibers used in the present invention may be optionally selected depending on the purpose, and is preferably 5 decitex to 100 decitex, and more preferably 10 decitex to 80 decitex.

[0029] The polyurethane fibers, which are further untreated, are preferably knitted with the polyamide fibers. The polyurethane fibers may be formed into a thread combined with the polyamide fibers or another thread covered with the polyamide fibers, and the resulting thread is preferably woven or interlaced. Such a thread includes, for example, an air-jet covered yarn (ACY) manufactured by simultaneously interlacing the polyurethane fiber and the polyamide fiber with an air processing machine, a single covered yarn (SCY), and a double covered yarn (DCY) which are manufactured by covering the polyamide fiber with the polyurethane fiber using a covering machine.

[0030] Mixed fabric of the polyamide fiber and the polyurethane fiber according to the present invention may be knitting, textile, or non-woven fabric, wherein the knitting includes warp-knitted fabric, circular-knitted fabric, weft-knitted fabric, and so on, such as tricot and raschel knitting. Knitting is preferable, and warp-knitted fabrics are more preferable. Since many wind-up rolls are necessary to manufacture tricot knitting, and which causes the tricot knitting to be smeared with oil used in knitting machines, application of the present invention to the tricot knitting is particularly preferable.

[0031] According to the present invention, the mixing ratio of the polyamide fiber to the polyurethane fiber is not limited, and the content of the polyurethane fiber in the mixed fabric is preferably 1% by weight to 50% by weight. The mixed fabric composed of the polyamide fiber and the polyurethane fiber may be further mixed with other synthetic fibers or natural fibers as long as the effects of the present invention are not reduced.

[0032] Since a continuous process in which fabrics are continuously fed into treating water is more efficient than a batch process in which the treating water is discarded after each operation, the mixed fabric according to the present invention is preferably scoured by the continuous process.

[0033] A continuous scouring apparatus such as an open soaper or a continuous relaxer is preferably used. According to the present invention, scouring treatment is preferably performed in a sequence of steps in order to prevent uneven dyeing. The continuous scouring apparatus is preferably provided with a plurality of treating tanks. The number of treating tanks is preferably 2 to 5 from the point of view of both investment efficiency and treating efficiency.

[0034] According to the present invention, the scouring treatment conditions are not limited and preferably include reflux treating. The scouring is preferably performed under conditions in which the temperature at the final step is higher than that at the starting step.

[0035] For example, in the continuous scouring apparatus, when the mixed fabric is fed into a first tank, a second tank, and a third tank in that order, the following conditions in which the temperature increases as the treatment progresses are preferable: a temperature of 50° C. in the first tank, a temperature of 60° C. in the second tank, and a temperature of 70° C. in the third tank.

[0036] The treating temperature is preferably 40° C. to 98° C. and more preferably at least 60° C. from the point of view of scouring efficiency.

[0037] In a scouring treatment according to the present invention, soft water is preferably used as the treating water. When using hard water containing metal ions such as calcium and magnesium ions, the following disadvantages may arise: a lowering of efficiency, and the uneven dyeing and a lowering of dyeing property due to the formation of complexes composed of metal ions and acid dyes. The concentration of metal ions in the water, which indicates total hardness, is preferably 40 ppm or less, and more preferably 30 ppm or less.

[0038] In the scouring treatment according to the present invention, the treating water needs to contain a sequestering agent.

[0039] In a continuous scouring process, the treating water after finishing the scouring treatment needs to contain an unreacted sequestering agent. The content of the unreacted sequestering agent remaining in the treating water is preferably at least 1 ppm, and more preferably at least 30 ppm.

[0040] The treating water contains the sequestering agent in a certain quantity such that metal ions such as calcium and magnesium in the treating water are sequestered and the content of the unreacted sequestering agent is at least 1 ppm. The content of the sequestering agent in the treating water is usually at least 0.1 g/L. While scouring mixed fabrics of polyamide fibers and polyurethane fibers, since the sequestering agent may be consumed by oil smears which adhere to the mixed fabric and contain metals, the quantity of the sequestering agent in the treating water preferably exceeds the above amount. In order to maintain the content of the sequestering agent at a proper level, the following method is preferably used: the content of the sequestering agent in the treating water is continuously or intermittently measured, and the content is controlled such that the treating water contains at least 1 ppm of the unreacted sequestering agent.

[0041] According to the present invention, the sequestering agent is preferably added in at least the initial step of the scouring treatment in order to improve the scouring effect by causing the mixed fabric to be in contact with the treating water for a suitably long time. For example, when using the above continuous scouring apparatus having the plurality of tanks, the sequestering agent is preferably fed into at least the first tank in which the mixed fabric is first treated.

[0042] According to the present invention, the sequestering agent is not specifically limited. Inorganic sequestering agents such as pyrophosphoric acid, tripolyphosphoric acid, trimetaphosphoric acid, and tetrametaphosphoric acid are preferably used. Also, the following organic sequestering agents containing nitrogen are preferably used: ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, nitrilotriacetic acid, and hydroxyethyliminodiacetic acid, which have a strong ability to sequester metal ions. Ethylenediaminetetraacetic acid and/or diethylenetriaminepentaacetic acid are particularly preferable.

[0043] The treating water preferably further contains polyphosphoric acid functioning as a dispersant in order to improve the dispersion of metal chelates, to prevent the metal chelates from adhering to the mixed fabric, and to prevent the metal chelates from precipitating.

[0044] The treating water used in the present invention may further contain a nonionic surfactant, an anionic surfactant, and an amphoteric surfactant, which are used in a usual scouring process, and may further contain an alkaline agent such as sodium hydroxide or soda ash. From the point of view of scouring efficiency, it is preferable to adjust the pH of the treating water to a proper value in response to the kind of the sequestering agent and the kind of the smear adhering to the mixed fabric.

[0045] A method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers according to the present invention will now be described.

[0046] In the manufacturing method, a mixed fabric of polyamide fibers and polyurethane fibers is scoured, and is preferably preset under the conditions of a temperature of 190° C. or less and a treating time of 60 s or less. The resulting mixed fabric is dyed and is then finished. The conditions of the presetting preferably further include dry heat. Also, the conditions of the presetting more preferably include a temperature of 187° C. or less and a treating time of 45 s or less. When the presetting temperature exceeds 190° C. or the presetting treating time exceeds 60 s, leveling is lowered due to a decrease in end amino groups, which are dyeing sites for acid dyes, caused by progress in thermal oxidation of the polyamide fiber.

[0047] The tentering rate of the presetting is preferably 40% or less of the width of the scoured fabric, and more preferably 30% or less.

[0048] A stretching rate of the presetting is preferably 5% or less of the length of the scoured fabric, and more preferably 0% or less. The presetting stretching rate is defined as the stretching rate in the longitudinal direction of the fabric at presetting, and 5% or less of the length of the scoured fabric defines that the stretching rate is within 5%.

[0049] According to the present invention, the occurrence of dyeing specks and stains due to oil smears containing metals is prevented.

[0050] As a result of intensive research, the inventors have discovered that the quality of fabrics is affected by dyeing conditions in addition to the scouring conditions and the presetting conditions.

[0051] That is, in a method for manufacturing a dyed mixed fabric according to the present invention, when a mixed fabric of polyamide fibers and polyurethane fibers is dyed with an acid dye, soft water is preferably used for the dyeing solution and the dyeing solution preferably contains a sequestering agent.

[0052] In the present invention, soft water is defined as water having a total hardness, which indicates the metal ion content in water, of 50 ppm or less and the soft water preferably has a total hardness of 40 ppm or less. The sequestering agent contained in the dyeing solution is preferably the same as the one used in the scouring step but may be a different one.

[0053] The content of the sequestering agent in the dyeing solution is preferably at least 0.1 g/L in general, wherein the content may be optionally selected in response to the content of residual oils and the degree of fouling after scouring and presetting.

[0054] The dyeing solution may contain a leveling agent and a pH adjuster in addition to the sequestering agent.

[0055] The dyeing temperature is not limited, preferably 70° C. to 120° C., and more preferably at least 80° C.

[0056] According to the present invention, the scouring treatment using the sequestering agent, the presetting, and the dyeing using the sequestering agent may be performed alone or in combination. Also, the above methods may be performed in combination with known techniques. The combination of optionally selected methods is preferably performed in response to the degree of fouling of the mixed fabric.

EXAMPLES

[0057] The present invention will now be described in detail with reference to the examples. Leveling is determined according to the following procedure.

[0058] (A) Leveling

[0059] A two-way tricot fabric was manufactured with a tricot machine (type HKS2, 180″×32G) fabricated by KARL MAYER TEXILMASCHINEN-FABRIK GmbH by arranging nylon 6 fibers at the front and by arranging polyether polyurethane fibers at the back. Pattern wheel oil used for the knitting machine was selected as an exemplary oil smear and was partly applied onto the two-way tricot fabric with a swab; and the resulting fabric was scoured and preset by methods including the method of the present invention, and was then dyed at 98° C. for 30 minutes using 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.). The dyed fabric was visually inspected for uneven dyeing. Examples having no dyeing specks were determined to be superior and other examples having any dyeing specks to be inferior.

Example 1

[0060] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.), 0.5 g/L of soda ash, and 3 g/L of ACROMER DH700 (an ethylenediaminetetraacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 90° C. for 10 minutes using soft water having a total hardness of 10 ppm. The resulting fabric was preset at 190° C. for 45 seconds and then dyed.

[0061] The dyed fabric had no oil smears or dyeing specks; hence, this example is excellent in level dyeing.

Example 2

[0062] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.), 0.5 g/L of soda ash, and 3 g/L of CLEWAT DP80 (an diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 90° C. for 10 minutes using soft water having a total hardness of 10 ppm. The resulting fabric was preset at 190° C. for 45 seconds and then dyed.

[0063] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Comparative Example 1

[0064] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.), 0.5 g/L of soda ash, and 3 g/L of CLEWAT DP80 (an diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 90° C. for 10 minutes using hard water having a total hardness of 100 ppm. The resulting fabric was preset at 190° C. for 90 seconds and then dyed.

[0065] In this comparative example, soft water was not used and the presetting time was longer. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Comparative Example 2

[0066] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) and 0.5 g/L of soda ash at 90° C. for 10 minutes using soft water having a total hardness of 10 ppm. The resulting fabric was preset at 193° C. for 45 seconds and then dyed.

[0067] In this comparative example, no sequestering agent was used and the presetting temperature was higher. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Example 3

[0068] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.), and 2,000 ppm of ACROMER DH700 (an ethylenediaminetetraacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 30 seconds with a dry heat setting apparatus, which was a pin tenter type, and then was dyed. After the scouring treatment, the used scouring solution in the second tank contained 250 ppm of the unreacted sequestering agent.

[0069] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Example 4

[0070] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) and 1,000 ppm of CLEWAT DP80 (a diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 30 seconds with a dry heat setting apparatus, which is a pin tenter type, and then was dyed. After the scouring treatment, the used scouring solution in the second tank contained 132 ppm of the unreacted sequestering agent.

[0071] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Example 5

[0072] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) and 300 ppm of CLEWAT DP80 (a diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 30 seconds with a dry heat setting apparatus, which is a pin tenter type, and then was dyed. After the scouring treatment, the used scouring solution in the second tank contained 34 ppm of the unreacted sequestering agent.

[0073] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Comparative Example 3

[0074] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) and 30 ppm of CLEWAT DP80 (a diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 90 seconds with a dry heat setting apparatus, which is a pin tenter type, and then was dyed. After the scouring treatment, the used scouring solutions in the first and second tanks both contained 0 ppm of the unreacted sequestering agent.

[0075] In this comparative example, no sequestering agent remained and the presetting time was longer. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Comparative Example 4

[0076] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 192° C. for 30 seconds with a dry heat setting apparatus, which is a pin tenter type, and then was dyed. After the scouring treatment, the used scouring solutions in the first and second tanks both contained 0 ppm of the unreacted sequestering agent.

[0077] In this comparative example, no sequestering agent was used and the presetting temperature was higher. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Example 6

[0078] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 30 seconds with a dry heat setting apparatus, which was a pin tenter type.

[0079] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of ACROMER DH700 (an ethylenediaminetetraacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 98° C. for 30 minutes using soft water having a total hardness of 10 ppm.

[0080] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Example 7

[0081] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 30 seconds with a dry heat setting apparatus, which was a pin tenter type.

[0082] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of CLEWAT DP80 (a diethylenetriaminepentaacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 98° C. for 30 minutes using soft water having a total hardness of 10 ppm.

[0083] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Comparative Example 5

[0084] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset at 190° C. for 90 seconds with a dry heat setting apparatus, which was a pin tenter type.

[0085] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.) at 98° C. for 30 minutes using hard water having a total hardness of 100 ppm.

[0086] In this comparative example, no sequestering agent was used and the presetting time was longer. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Example 8

[0087] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) at 90° C. for 1 minute. The resulting fabric was preset with a dry heat setting apparatus, which was a pin tenter type, under the following conditions: a tentering rate of 30%, an overfeed rate of 0%, a temperature of 187° C., and a time of 45 seconds.

[0088] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.) at 98° C. for 30 minutes.

[0089] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Comparative Example 6

[0090] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.) at 90° C. for 1 minute. The resulting fabric was preset with a dry heat setting apparatus, which was a pin tenter type, under the following conditions: a tentering rate of 45%, an overfeed rate of −10%, a temperature of 195° C., and a time of 90 seconds.

[0091] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.) at 98° C. for 30 minutes.

[0092] In this comparative example, no sequestering agent was used and the presetting temperature was higher. The dyed fabric had some oil smears and striking dyeing specks due to the oil smears; hence, this comparative example is poor in level dyeing.

Example 9

[0093] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.), 0.5 g/L of soda ash, and 3 g/L of ACROMER DH700 (an ethylenediaminetetraacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 90° C. for 10 minutes using soft water having a total hardness of 10 ppm. The resulting fabric was preset with a dry heat setting apparatus, which was a pin tenter type, under the following conditions: a tentering rate of 30%, a overfeed rate of 0%, a temperature of 187° C., and a time of 45 seconds.

[0094] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.) at 98° C. for 30 minutes.

[0095] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

Example 10

[0096] The fabric was scoured with a scouring solution containing 2 g/L of SUNMORL BL650 (a nonionic surfactant manufactured by NICCA CHEMICAL Co., Ltd.). The scouring treatment was performed using a continuous scouring apparatus, which was an open soaper type and had 2 treating tanks, under the following conditions: a temperature of 60° C. in the first tank, a temperature of 90° C. in the second tank, and a treating time of 30 seconds. The resulting fabric was preset with a dry heat setting apparatus, which was a pin tenter type, under the following conditions: a tentering rate of 30%, an overfeed rate of 0%, a temperature of 187° C., and a time of 45 seconds.

[0097] The resulting fabric was dyed with a dye solution containing 0.5% owf of kayanol milling turquoise blue 3G (an acid dye manufactured by Nippon Kayaku Co., Ltd.), 4% owf of NEWBON SD-2 (an anion leveling agent manufactured by NICCA CHEMICAL Co., Ltd.), 0.3 g/L of NC ACID W (a pH adjuster manufactured by NICCA CHEMICAL Co., Ltd.), and 0.3 g/L of ACROMER DH700 (an ethylenediaminetetraacetic acid sequestering agent manufactured by Teikoku Chemical Industries Co., Ltd.) at 98° C. for 30 minutes using soft water having a total hardness of 10 ppm.

[0098] The dyed fabric had no oil smears and dyeing specks; hence, this example is excellent in level dyeing.

INDUSTRIAL APPLICABILITY

[0099] According to the present invention, a mixed fabric of polyamide fibers and polyurethane fibers is provided, wherein the mixed fabric has no dyeing specks and is excellent in leveling. The mixed fabric of the present invention is suitable for innerwear, pantyhose, swimming wear, leotards, and outerwear, and has an extremely high practical use. 

1. A method for scouring a mixed fabric of polyamide fibers and polyurethane fibers, characterized in that soft water as treating water is used and the treating water contains a sequestering agent.
 2. A method for continuously scouring a mixed fabric of polyamide fibers and polyurethane fibers, characterized in that treating water after finishing scouring treatment contains an unreacted sequestering agent.
 3. The method for scouring a mixed fabric of polyamide fibers and polyurethane fibers according to claim 2, wherein the scouring is performed by a plurality of scouring steps and the sequestering agent is added at least at the first step.
 4. The method for scouring a mixed fabric of polyamide fibers and polyurethane fibers according to claim 1 or 2, wherein the sequestering agent is ethylenediaminetetraacetic acid and/or diethylenetriaminepentaacetic acid.
 5. The method for scouring a mixed fabric of polyamide fibers and polyurethane fibers according to claim 1 or 2, wherein the treating water further contains a dispersant.
 6. A method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers, characterized in that the method comprises the steps of scouring a mixed fabric of polyamide fibers and polyurethane fibers, presetting the mixed fabric at 190° C. or less for 60 seconds or less, dyeing the mixed fabric, and finishing the mixed fabric.
 7. The method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers according to claim 6, wherein a tentering rate in the presetting step is 40% or less of the width of the scoured fabric.
 8. The method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers according to claim 6, wherein a stretching rate in the presetting step is 5% or less of the length of the scoured fabric.
 9. A method for manufacturing a dyed mixed fabric of polyamide fibers and polyurethane fibers, characterized in that the method comprises the step of dyeing a mixed fabric of polyamide fibers and polyurethane fibers with an acid dye, wherein soft water as a dyeing solution is used and the dyeing solution contains a sequestering agent.
 10. A dyed mixed fabric of polyamide fibers and polyurethane fibers manufactured by the method according to claim 6 or
 9. 11. The dyed mixed fabric of polyamide fibers and polyurethane fibers according to claim 10, wherein the dyed mixed fabric is a knitted fabric.
 12. The dyed mixed fabric of polyamide fibers and polyurethane fibers according to claim 10, wherein the dyed mixed fabric is a warp-knitted fabric. 